Motor control device

Abstract

A motor control device includes: a feedforward computing section for computing a motion reference value and a feedforward driving force based on a motion command; a deviation compensation computing section for outputting a deviation compensation driving force by a control computation for reducing a control deviation; a driving-force command synthesizing section for outputting a driving-force command based on the feedforward driving force and the deviation compensation driving force; a reaction-force compensation computing section for computing a motion correction value based on a predetermined reaction-force reference value and the deviation compensation driving force; and a control-deviation computing section for computing the control deviation based on a deviation between the motion reference value and a motor motion detection value, and the motion correction value.

The invention claimed is: 
     
       1. A motor control device for outputting a driving-force command to a current controller of a motor based on a motion command for a motion of the motor as a speed or a position and a motor motion detection value corresponding to a result of detection of the motion, the motor control device comprising:
 a feedforward computing section for computing a motion reference value corresponding to a reference signal for the motion of the motor and a feedforward driving force based on the motion command; 
 a deviation compensation computing section for receiving a control deviation determined by a predetermined computation as an input to output a result of a control computation including an integral computation as a deviation compensation driving force, the control computation being performed by using a preset control parameter so as to reduce the control deviation; 
 a driving-force command synthesizing section for outputting the driving-force command to the current controller by a computation for obtaining a sum of the feedforward driving force and the deviation compensation driving force as steady characteristics based on the feedforward driving force and the deviation compensation driving force; 
 a reaction-force compensation computing section for computing a motion correction value based on a predetermined reaction-force reference value and the deviation compensation driving force; and 
 a control-deviation computing section for computing the control deviation based on a deviation between the motion reference value and the motor motion detection value, and the motion correction value. 
 
     
     
       2. A motor control device according to  claim 1 , wherein the driving-force command synthesizing section computes the driving-force command by a computation for removing a predetermined frequency component from the deviation compensation driving force. 
     
     
       3. A motor control device according to  claim 1 ,
 wherein the reaction-force compensation computing section includes:
 a driving-force correction-amount computing section for computing a driving-force correction amount by comparison between the predetermined reaction-force reference value and the deviation compensation driving force; and 
 a reaction-force compensation amplifying section for multiplying the driving-force correction amount by a reaction-force compensation gain, and 
 
 wherein the reaction-force compensation computing section computes the motion correction value based on an output of the reaction-force compensation amplifying section. 
 
     
     
       4. A motor control device according to  claim 3 , wherein the reaction-force compensation computing section further includes a reaction-force compensation limiter for outputting, as the motion correction valve, a value obtained after limiting an output calculated by the reaction-force compensation amplifying section with a predetermined magnitude. 
     
     
       5. A motor control device according to  claim 3 ,
 wherein the deviation compensation computing section outputs the deviation compensation driving force by performing a proportional-integral computation on the control deviation, and 
 wherein the reaction-force compensation computing section includes a reaction-force compensation filter for allowing a low-pass filter to act on the output of the reaction-force compensation amplifying section, and sets a pole of the low-pass filter based on a zero point of the deviation compensation computing section. 
 
     
     
       6. A motor control device according to  claim 3 , wherein the deviation compensation computing section computes the deviation compensation driving force by a computation for allowing a transfer function from the control deviation to the deviation compensation driving force to have an integral characteristic. 
     
     
       7. A motor control device according to  claim 3 , wherein the reaction-force compensation computing section sets the reaction-force compensation gain based on the preset control parameter of the deviation compensation computing section. 
     
     
       8. A motor control device according to  claim 1 , further comprising a master-axis control unit for generating a master-axis driving-force command to a current controller for a master-axis motor mechanically coupled to the motor,
 wherein the master-axis control unit outputs a signal having a predetermined relation with the master-axis driving-force command to the reaction-force compensation computing section as the predetermined reaction-force reference value. 
 
     
     
       9. A motor control device according to  claim 8 ,
 wherein the master-axis control unit includes:
 a master-axis feedforward computing section for computing a master-axis motion reference value corresponding to a reference signal for a motion of the master-axis motor and a master-axis feedforward driving force based on the motion command; 
 a master-axis control-deviation computing section for computing a master-axis control deviation by subtracting a master-axis motor motion detection value obtained by detecting the motion of the master-axis motor from the master-axis motion reference value; 
 a master-axis deviation compensation computing section for receiving the master-axis control deviation as an input to output, as a master-axis deviation compensation driving force, a result of a control computation performed so as to reduce the master-axis control deviation; and 
 a master-axis driving-force command synthesizing section for computing and outputting the master-axis deriving-force command to the current controller for the master-axis motor based on the master-axis feedforward driving force and the master-axis deviation compensation driving force, and 
 
 wherein the master-axis control unit outputs the master-axis deviation compensation driving force to the reaction-force compensation computing section as the predetermined reaction-force reference value. 
 
     
     
       10. A motor control device according to  claim 1 , wherein the control-deviation computing section performs switching between a first mode in which the control deviation is computed without using the motion correction value and a second mode in which the control deviation is computed based on the motion correction value, based on a predetermined mode switching signal during a control operation, to output the control deviation.